The FBI has warned of possible armed protests across the US as Trump supporters and far-right groups call for demonstrations before Joe Biden is sworn in as president.
There are reports of armed groups planning to gather at all 50 state capitols and in Washington DC in the run-up to his 20 January inauguration.
Security will be tight for the event after a pro-Trump mob stormed Congress.
House Democrats say a vote to impeach the president will happen on Wednesday.
They accuse President Trump of "incitement of insurrection" and say the vote will be held unless Vice-President Mike Pence invokes constitutional powers to remove Mr Trump from office. There is no sign Mr Pence is prepared to do so.